<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .textcolor {
        color: #f00;
      }
      div span {
        color: purple;
      }
    </style>
  </head>
  <body>
    <p>段落1</p>
    <p class="textcolor">段落2</p>
    ">
    <p>段落3</p>
    <p class="textcolor">段落4</p>
    <button class="textcolor">按钮</button>

    <span>外面的span</span>
    <div>
      <span>里面的span</span>
    </div>
  </body>
</html>
